BAEL-2174: proxies in core java (eugenp#5628)

Author: chrisoberle

core-java/src/main/java/com/baeldung/networking/proxies/CommandLineProxyDemo.java

@@ -0,0 +1,17 @@
+package com.baeldung.networking.proxies;
+
+import java.net.URL;
+import java.net.URLConnection;
+
+public class CommandLineProxyDemo {
+
+ public static final String RESOURCE_URL = "http://www.google.com";
+
+ public static void main(String[] args) throws Exception {
+
+ URL url = new URL(RESOURCE_URL);
+ URLConnection con = url.openConnection();
+ System.out.println(UrlConnectionUtils.contentAsString(con));
+ }
+
+}

core-java/src/main/java/com/baeldung/networking/proxies/DirectProxyDemo.java

@@ -0,0 +1,20 @@
+package com.baeldung.networking.proxies;
+
+import java.io.IOException;
+import java.net.HttpURLConnection;
+import java.net.Proxy;
+import java.net.URL;
+
+public class DirectProxyDemo {
+
+ private static final String URL_STRING = "http://www.google.com";
+
+ public static void main(String... args) throws IOException {
+
+ URL weburl = new URL(URL_STRING);
+ HttpURLConnection directConnection 
+ = (HttpURLConnection) weburl.openConnection(Proxy.NO_PROXY);
+ System.out.println(UrlConnectionUtils.contentAsString(directConnection));
+ }
+
+}

core-java/src/main/java/com/baeldung/networking/proxies/SocksProxyDemo.java

@@ -0,0 +1,32 @@
+package com.baeldung.networking.proxies;
+
+import java.io.IOException;
+import java.net.HttpURLConnection;
+import java.net.InetSocketAddress;
+import java.net.Proxy;
+import java.net.Socket;
+import java.net.URL;
+
+public class SocksProxyDemo {
+
+ private static final String URL_STRING = "http://www.google.com";
+ private static final String SOCKET_SERVER_HOST = "someserver.baeldung.com";
+ private static final int SOCKET_SERVER_PORT = 1111;
+
+ public static void main(String... args) throws IOException {
+
+ URL weburl = new URL(URL_STRING);
+ Proxy socksProxy 
+ = new Proxy(Proxy.Type.SOCKS, new InetSocketAddress("127.0.0.1", 1080));
+ HttpURLConnection socksConnection 
+ = (HttpURLConnection) weburl.openConnection(socksProxy);
+ System.out.println(UrlConnectionUtils.contentAsString(socksConnection));
+
+ Socket proxySocket = new Socket(socksProxy);
+ InetSocketAddress socketHost 
+ = new InetSocketAddress(SOCKET_SERVER_HOST, SOCKET_SERVER_PORT);
+ proxySocket.connect(socketHost);
+ // do stuff with the socket
+ }
+
+}

core-java/src/main/java/com/baeldung/networking/proxies/SystemPropertyProxyDemo.java

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+package com.baeldung.networking.proxies;
+
+import java.net.URL;
+import java.net.URLConnection;
+
+public class SystemPropertyProxyDemo {
+
+ public static final String RESOURCE_URL = "http://www.google.com";
+
+ public static void main(String[] args) throws Exception {
+
+ System.setProperty("http.proxyHost", "127.0.0.1");
+ System.setProperty("http.proxyPort", "3128");
+
+ URL url = new URL(RESOURCE_URL);
+ URLConnection con = url.openConnection();
+ System.out.println(UrlConnectionUtils.contentAsString(con));
+
+ System.setProperty("http.proxyHost", null);
+ // proxy will no longer be used for http connections
+ }
+
+}

core-java/src/main/java/com/baeldung/networking/proxies/UrlConnectionUtils.java

@@ -0,0 +1,21 @@
+package com.baeldung.networking.proxies;
+
+import java.io.BufferedReader;
+import java.io.IOException;
+import java.io.InputStreamReader;
+import java.net.URLConnection;
+
+class UrlConnectionUtils {
+
+ public static String contentAsString(URLConnection con) throws IOException {
+ StringBuilder builder = new StringBuilder();
+ try (BufferedReader reader 
+ = new BufferedReader(new InputStreamReader(con.getInputStream()))){
+ while (reader.ready()) {
+ builder.append(reader.readLine());
+ }
+ }
+ return builder.toString();
+ }
+
+}

core-java/src/main/java/com/baeldung/networking/proxies/WebProxyDemo.java

@@ -0,0 +1,23 @@
+package com.baeldung.networking.proxies;
+
+import java.io.IOException;
+import java.net.HttpURLConnection;
+import java.net.InetSocketAddress;
+import java.net.Proxy;
+import java.net.URL;
+
+public class WebProxyDemo {
+
+ private static final String URL_STRING = "http://www.google.com";
+
+ public static void main(String... args) throws IOException {
+
+ URL weburl = new URL(URL_STRING);
+ Proxy webProxy 
+ = new Proxy(Proxy.Type.HTTP, new InetSocketAddress("127.0.0.1", 3128));
+ HttpURLConnection webProxyConnection 
+ = (HttpURLConnection) weburl.openConnection(webProxy);
+ System.out.println(UrlConnectionUtils.contentAsString(webProxyConnection));
+ }
+
+}